With progress and development of recent semiconductor processes, it became possible to form a most part of a high-frequency circuit into a semiconductor chip, including a capacitor for high-frequency signal transmission.
When a capacitor for high-frequency signal transmission is formed on a silicon substrate, since there are a parasitic capacitance and a parasitic resistance between a capacitor electrode and a silicon substrate, an undesirable problem may occur, in which a high-frequency signal to be normally flowed through the capacitor does not flow through the capacitor, but flows through a silicon substrate via the parasitic capacitance and the parasitic resistance. This undesirable problem is called as a substrate loss.
In order to reduce such a substrate loss, a new measure has been proposed in which a shield made of a conductive material is disposed between the capacitor electrode and the silicon substrate, and this shield is grounded. However, when miniaturization of the semiconductor device progresses, there may be no space to form the shield made of a flat pattern, and thus a large number of through-holes have to be formed on the shield. When the through-holes are formed on the shield, the high-frequency signal leaks out from the capacitor electrode to the silicon substrate, and as a result, the function of the shield itself such as reduction of the substrate loss may be unable to be fulfilled.